BECHER, Johann Joachim, a German chemist, born in Spire in 1625, died in London in October, 1682. In spite of adverse circumstances, he acquired a knowledge of medicine, physics, and chemistry, became professor at Mentz, and in 1660 imperial councillor at Vienna and first physician to the elector of Bavaria. He endeavored to promote industry and a spirit of enterprise in Vienna, but incurred the displeasure of the court, and after many unfortunate experiences in various places he ended his life in London. His fame rests on his Physica Subterranea, (Frankfort-on-the-Main, 1669), establishing a close relation between chemistry and medical science, and on his founding the theoretical basis of chemistry.